The present application relates to an ear canal fitting unit and a biological signal measuring device and is suitable for e.g. a technical field of acquiring waves generated and transmitted in a biological body as an electrical signal.
As a related art, there has been proposed an ear canal electrode unit that extracts brain waves or the like by using a spring-shape electrode inserted into an ear canal (refer to e.g. Japanese Patent Laid-open No. 2008-67911).